Just a quick question, because I can't seem to find an answer to this -

I am profiling my LCD monitor using Spyder 2. Should I do this with the normal ambient light in the room on (falling on the screen as it normally does) or with the ambient light off and in a dark room?

Many thanks

John

« Last Edit: May 18, 2010, 03:56:25 AM by John R Smith »

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Hasselblad 500 C/M, SWC and CFV-39 DBand a case full of (very old) lenses and other bits

Just a quick question, because I can't seem to find an answer to this -

I am profiling my LCD monitor using Spyder 2. Should I do this with the normal ambient light in the room on (falling on the screen as it normally does) or with the ambient light off and in a dark room?

Many thanks

John

You should do it with the lighting as it normally is when you are editing photos. This should be fairly dim light, although some people prefer to edit in total darkness (Why? Beats me). In any event, the room lighting is unlikely to affect the calibration if your puck is flat against the screen as it should be.

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Peter"Photographic technique is a means to an end, never the end itself."View my web pageView my Facebook page

I confirm what Walter says about the hood. You would be amazed at how much contrast is lost because your shadows are all washed out by the ambient light shining directly on the screen. Any kind of hood to prevent direct overhead light from falling on the screen would be good.

As suggested for best practices while working the ambient light should be controlled, or you will get contrast reducing flare if you are on a matt display or bothersome reflections if your display happens to be a glossy one. However, I don't believe the ambient light will actually affect the profile itself unless it's pretty bright ...

I go against what all the rest say. I cover my monitor with a black cloth when profiling. The puck is reading from the screen and I don't want any ambient light leaking in from the sides. All of the above advice is great for viewing, but I have been told by a consultant that you want as pure a reading as you can get from the screen.

I go against what all the rest say. I cover my monitor with a black cloth when profiling. The puck is reading from the screen and I don't want any ambient light leaking in from the sides. All of the above advice is great for viewing, but I have been told by a consultant that you want as pure a reading as you can get from the screen.

There is a large amount of truth to this. Your goal is to measure the output of your display, not the ambient lighting. Different measurement pucks and display technologies are affected differently by ambient light. what you want to avoid is the sensor picking up light scattered from the sides. If the sensor is reading light that comes from the room rather than the display, you will not have any accuracy in the screen's shadow response. We have characterized a number of measurement pucks for an upcoming report on sensor accuracy and found large (>15 DE) differences in measured black levels when comparing low light vs. typical office lighting for the ambient. The worst pucks in this regard were the i1-Pro and Spyder 3, the best the i1-Display.

Draping a cloth over the monitor works in a brightly lit environment. If you have control of the light switch, however, this is a better approach. Some sensors are prone to overheating and skewing the calibration levels. This is compounded if you use profiling software that takes a long time to do its thing.

As far as viewing environments go, the comments by Pat, Andrew, and Walter are spot-on. Avoid having light shining directly on your screen. A simple hood makes a major difference.

The overall lighting level should not be overly bright, but today's LCD screens allow more flexibility than past models. Decent quality graphics displays offer the best overall color gamut and output smoothness when run at a luminance of at least 140 cd/m2. If your editing environment is still tuned to the 80 cd/m2 luminance of yesteryear's CRT displays, this will seem blindingly bright. If so, come on out of the cave!

If your ambient light is too bright you will not see the full black range your display shows. Profiling the screen with the light on will not help; the software tries to compensate for light that does not originate from the display. The result is a profile with poor shadow definition and, usually, a color cast as well.

Right. A bit like the hoods that come with Eizo screens, I suppose. What is foamcore?

John

Foamcore is 5mm or so of polythene foam sandwiched between card or thin plastic sheet to form a very light but stiff board usually used for mounting photos. You can cut it with a steel ruler and a scalpel, glue it or gaffer tape it together to form an effective and very cheap monitor hood, attach to the monitor using self adhesive velcro fixings on both hood and monitor.

Foamcore is 5mm or so of polythene foam sandwiched between card or thin plastic sheet to form a very light but stiff board usually used for mounting photos. You can cut it with a steel ruler and a scalpel, glue it or gaffer tape it together to form an effective and very cheap monitor hood, attach to the monitor using self adhesive velcro fixings on both hood and monitor.

Thanks Pete. This is not something that I've come across, I'm still back in the mounting board era. I shall try to find some foamcore at our local art shop. And then gaffer tape and blu-tac will be my weapons of choice. Perhaps I shall build an enormous hood that fully encloses the operator, with just a small vent to let tobacco smoke out at the top

John

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Hasselblad 500 C/M, SWC and CFV-39 DBand a case full of (very old) lenses and other bits

Right. A bit like the hoods that come with Eizo screens, I suppose....

I have a home made matte black foam core hood on my LCD. It cost around $10 for the board and the art supply store cut it for me on their huge matting table. It's held on with a few pieces of Velcro tape and has a hinged opening to accommodate the calibrator puck. Here's a link to a simple hood design:

Just a little inadvertently acquired experience: I usually do both my work and my calibration with the main room lights off. The other day I started a calibration and left the room. Without my noticing, a family member turned on the lights and entered the room. The calibration was WAY off! I ran it again with the lights off and it was OK. So, at least for the puck that comes with the NEC 2690wuxi2, ambient light is definitely detected.

A black cloth and a darken room seems extreme to me - you will probably see more shadow detail on the display than you would ever get in a print.

I believe the best viewing conditions would be dim ambient viewing light and a "hooded" monitor with a separate "brighter" light that is representative of the final "hanging" brightness were the prints will be viewed.

NEC's SpectraView software references an ISO Standard 12646 for the ambient light condition for displays used in critical color applications. If you have a ColorMunki you can determine the "Ambient Light Measurement" in your viewing area.BobD

For those who use the 'cover the screen with a black cloth' approach, how do you make adjustments to the screen? That is, how do you adjust the brightness/backlight, colour temp, etc? Or do you put the software on autopilot so no user intervention is needed and let the profile make up the difference between measured and desired?

Bob, wrt the ISO standard the NEC device is comparing to, I'm admittedly no expert on ISO standards but I believe 12646 was written more for press environments. Standard 3664 is more aimed at photo editing and suggests ambient lighting in the range of 32 to 64 lux and a monitor brightness in the range of 75 to 100 cd/m^2 which, in my view, is too dim; particularly with today's LCD monitors. As others have noted, dimmer light for editing is better and not having light shining directly on the screen is also much better. I'd add that the lighting in the room being diffused (i.e., through a frosted glass shade) is also a good idea.

For those who use the 'cover the screen with a black cloth' approach, how do you make adjustments to the screen? That is, how do you adjust the brightness/backlight, colour temp, etc? Or do you put the software on autopilot so no user intervention is needed and let the profile make up the difference between measured and desired?

With the NEC monitors and Spectraview software, unless you are adjusting the individual primaries to get one monitor to match another, you simply set up the target settings and let the software put the monitor through its paces until the profiling/calibration is done. The software controls the monitor's lookup tables and resets the computer's video card to have no influence on its lookup tables.

With the NEC monitors and Spectraview software, unless you are adjusting the individual primaries to get one monitor to match another, you simply set up the target settings and let the software put the monitor through its paces until the profiling/calibration is done. The software controls the monitor's lookup tables and resets the computer's video card to have no influence on its lookup tables.